LS1 241 casting ported heads, valves and springs
08-13-2009, 02:00 PM
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LS1 241 casting ported heads and valves Hand ported and milled .025 with a 3 angle valve job. These heads should be good for a minimum of a 25 rwhp gain.
Will sacrifice for $soldplus shipping, with a new set of Patriot Gold springs add $200.00 installed. Shipping will add apx $40.00 to $50.00
Will sacrifice for $soldplus shipping, with a new set of Patriot Gold springs add $200.00 installed. Shipping will add apx $40.00 to $50.00
Last edited by JeremyF; 10-22-2009 at 01:14 PM. Reason: Deleted springs from post
09-03-2009, 11:08 AM
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Adding a dyno sheet Here is an example of another set of these heads on an 06 GTO with a 236/238/ 602 605 cam. Th before is with out our ported heads and ported FAST, the after is with both. We do not have flow #s but wanted to give an example of what really matters - the horsepower and torque improvements
The vehicle picked up 56 rwhp and 59 rwtq with our ported heads and our ported FAST:
The vehicle picked up 56 rwhp and 59 rwtq with our ported heads and our ported FAST:
09-09-2009, 01:36 PM
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Many fret over head flow numbers, while not many people are flowing heads with intake manifolds attached. It is quite an eye opener to see a 300+ CFM open port fall to under 250CFM with an LS2 manifold on it. On one of our earliest LS2 port designs in '05 we picked up over 10 cfm per port, our ports have been
refined dramatically and I would expect significantly more than that currently. We spend a many days a week on the dyno testing new things, and not all of them are home runs but we
are always learning.
What I am getting at is it depends on the application and optimizing EVERY component along the way in the induction stream as well as the exhaust.
One must look at the whole picture not only the heads or the flow numbers but velocity especially the closer the back of the valve. We have seen many heads that flow incredible numbers flop for that application, Eg. a 239CC intake runner on a 346 CID makes barely 400rwhp and 380RWTQ w/ a mid 230s cam, However that same head on a 408 would make 500RWHP and 480RWTQ, air speed is very different. It is not gross flow number but how well the cylinder is being filled is determined by air speed at a given rpm.
I often tell people that anyone can port a huge hole in a cylinder head and say it flows over 300cfm the art is in keeping the port the right size, smaller but higher air speed. One cannot make HP without gaining TQ, and one cannot make tq without gaining Volumetric efficiency (or how well you fill a cylinder). Now I dont know that magic number of Mach or the air speed but I would Imagine that higher is better up until the choking point, but you have to consider avg valve lift and given RPM of desired peak power etc.
refined dramatically and I would expect significantly more than that currently. We spend a many days a week on the dyno testing new things, and not all of them are home runs but we
are always learning.
What I am getting at is it depends on the application and optimizing EVERY component along the way in the induction stream as well as the exhaust.
One must look at the whole picture not only the heads or the flow numbers but velocity especially the closer the back of the valve. We have seen many heads that flow incredible numbers flop for that application, Eg. a 239CC intake runner on a 346 CID makes barely 400rwhp and 380RWTQ w/ a mid 230s cam, However that same head on a 408 would make 500RWHP and 480RWTQ, air speed is very different. It is not gross flow number but how well the cylinder is being filled is determined by air speed at a given rpm.
I often tell people that anyone can port a huge hole in a cylinder head and say it flows over 300cfm the art is in keeping the port the right size, smaller but higher air speed. One cannot make HP without gaining TQ, and one cannot make tq without gaining Volumetric efficiency (or how well you fill a cylinder). Now I dont know that magic number of Mach or the air speed but I would Imagine that higher is better up until the choking point, but you have to consider avg valve lift and given RPM of desired peak power etc.
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10-15-2009, 07:11 AM
#17
Good lord, what a great price! Bump up for some good ported 241 heads.
A lot of people might dis the ported 241 heads but they do perform rather well if they are ported right and these are!
For anyone that wants a budget build, this would be a great start.
A lot of people might dis the ported 241 heads but they do perform rather well if they are ported right and these are!
For anyone that wants a budget build, this would be a great start.
